With lime in farming we usually used 3 types. 1) pelleted, 2) ground, and 3) granular. All three can take up to a month or more to dissolve, depending on how much moisture you get, although ground lime dissolves the quickest, (usually after the first hard rain of 1/2 inch or more) Pelleted is meant to dissolve slowly or be time released. Granular is middle ground between the others-
Like I said earlier, depends on how much moisture you get- don't know about how harmful lime is, but do know if they lick it off their(especially the ground lime) paws it will probably upset their stomachs- hope this helps